By Martyn Herman RIO DE JANEIRO, Aug 17 (Reuters) - To the untrained eye Rio's green and red Olympic BMX track can, at first glance, look like a giant crazy golf course, not a place where gold medals will be won and lost on Friday. After the thrills and spills of the Olympics road races and the high-speed, high-tech track action in the velodrome, Wednesday gave the BMX cyclists the chance to shine as the men's and women's seeding runs took place at the Deodoro circuit. Last to go, accompanied by roars from large Colombian contingent in the stands, was world champion Mariana Pajon. More...